Fish Surveys

Published

May 9, 2024

Metadata

Figure 1: Location of fish surveys
Table 1: Summary of work by island and exposure
Number of fish surveys per location, habitat, and exposure
Exposure Strata # Sites # Transects # Reels Surveyed distance (m)
Fanna
Forereef Leeward 2 1 2 6 150
Forereef Windward 2 5 10 30 750
Total — — 6 12 36 900
Helen
Backreef Lagoon 1 1 2 6 150
Patchreef Lagoon 2 3 6 18 450
Forereef Leeward 2 6 12 36 900
Forereef Windward 2 5 10 30 750
Total — — 15 30 90 2250
Merir
Forereef Leeward 2 3 6 18 450
Forereef Windward 2 4 8 24 600
Total — — 7 14 42 1050
Pulo Anna
Forereef Leeward 2 2 4 12 300
Forereef Windward 2 2 4 12 300
Total — — 4 8 24 600
Sonsorol
Forereef Leeward 2 4 8 24 600
Forereef Windward 2 3 6 18 450
Total — — 7 14 42 1050
Tobi
Forereef Leeward 2 5 10 30 750
Forereef Windward 2 1 2 6 150
Total — — 6 12 36 900
Grand total — — 45 90 270 6750

QA/QC

Taxa

Observations

Expedition Summary

Table 2: Summary of results
Average species richness, abundance, and biomass
Sites # Transects # Reels # Taxa Abundance (ind/m2)1 Biomass (g/m2)1
By exposure
Lagoon 4 8 24 67.88 8.04 (7.53) 198.31 (66.52)
Leeward 21 42 126 67.29 9.64 (6.72) 567.37 (221.58)
Windward 20 40 120 72.88 12.94 (8.39) 753.30 (473.41)
By strata
Deep 44 45 135 69.44 10.42 (7.46) 696.17 (446.38)
Shallow 44 45 135 70.20 11.51 (8.00) 538.23 (290.19)
Overall
Total 45 90 270 69.82 10.96 (7.71) 617.20 (382.68)
1 Standard deviation in parenthesis

Location summary

Table 3: Summary of results by island and depth strata.
Average species richness, abundance, and biomass by location
Sites # Transects # Reels # Taxa Abundance (ind/m2) Biomass (g/m2)
Fanna
Deep 6 6 18 77.50 13.76 637.42
Shallow 6 6 18 60.83 14.36 297.62
Overall — 12 36 69 14 468
Helen
Deep 14 15 45 67.80 6.82 633.74
Shallow 14 15 45 74.87 9.73 601.14
Overall — 30 90 71 8 617
Merir
Deep 7 7 21 67.57 6.33 730.30
Shallow 7 7 21 73.43 5.68 634.89
Overall — 14 42 70 6 683
Pulo Anna
Deep 4 4 12 61.25 17.72 1203.83
Shallow 4 4 12 67.50 10.43 670.61
Overall — 8 24 64 14 937
Sonsorol
Deep 7 7 21 72.57 17.38 493.91
Shallow 7 7 21 64.00 17.22 382.62
Overall — 14 42 68 17 438
Tobi
Deep 6 6 18 69.50 7.87 768.69
Shallow 6 6 18 73.17 13.96 602.09
Overall — 12 36 71 11 685

Analyses

Richness

Figure 2: Number of species by order and family
Figure 3: Species richnnes by island
Table 4: Results of Adonis model for univariate analysis of fish species richness
Results of Adonis model for univariate analysis of fish species richness
df SumOfSqs R2 statistic p.value
depth_strata 1 17.187 0.001 0.134 0.721
location 5 700.063 0.061 1.095 0.391
exposure 1 865.000 0.075 6.763 0.016
habitat 1 17.074 0.001 0.133 0.720
diver 1 18.771 0.002 0.147 0.701
Residual 79 10104.930 0.877 NA NA
Total 89 11527.156 1.000 NA NA
Figure 4: Species richnnes by exposure by island

Abundance

Figure 5: Fish abundance by island
Table 5: Results of Adonis model for univariate analysis of fish abundance
Results of Adonis model for univariate analysis of fish abundance
df SumOfSqs R2 statistic p.value
depth_strata 1 29.318 0.006 0.767 0.397
location 5 1245.230 0.235 6.515 0.001
exposure 1 229.449 0.043 6.003 0.021
habitat 1 2.019 0.000 0.053 0.821
diver 1 695.530 0.132 18.196 0.001
Residual 79 3019.706 0.571 NA NA
Total 89 5289.048 1.000 NA NA
Figure 6: Abundance by exposure by diver
Figure 7: Abundance by exposure by island

Biomass

Figure 8: Fish biomass (g/m2) by island
Table 6: Results of Adonis model for univariate analysis of fish biomass
Results of Adonis model for univariate analysis of fish biomass
df SumOfSqs R2 statistic p.value
diver 1 117916.70 0.009 1.225 0.269
depth_strata 1 559337.70 0.043 5.812 0.012
habitat 1 10482.94 0.001 0.109 0.718
exposure 1 1172378.50 0.090 12.182 0.001
location 5 2491926.10 0.191 5.179 0.002
Residual 79 7602837.73 0.583 NA NA
Total 89 13033627.90 1.000 NA NA

By depth

Figure 9: Biomass by depth strata by island

By exposure

Figure 10: Biomass by exposure by island
Table 7: Summary of results by island and exposure
Average species richness, abundance, and biomass by location and exposure
Sites # Transects # Reels # Taxa Abundance (ind/m2) Biomass (g/m2)
Fanna
Leeward 1 2 6 69.50 10.40 615.14
Windward 5 10 30 69.10 14.79 437.99
Helen
Lagoon 4 8 24 67.88 8.04 198.31
Leeward 6 12 36 66.42 6.01 502.66
Windward 5 10 30 80.00 11.18 1090.49
Merir
Leeward 3 6 18 68.17 5.40 760.32
Windward 4 8 24 72.25 6.46 624.30
Pulo Anna
Leeward 2 4 12 62.00 13.51 578.92
Windward 2 4 12 66.75 14.64 1295.53
Sonsorol
Leeward 4 8 24 65.50 13.97 383.90
Windward 3 6 18 72.00 21.74 510.75
Tobi
Leeward 5 10 30 70.90 11.36 661.85
Windward 1 2 6 73.50 8.67 803.09

By family

Figure 11: Biomass by family
Figure 12: Biomass by family and depth strata

By trophic group

Figure 13: Biomass by trophic group

By species

Figure 14: Frequency, abundance, and biomass by species
Table 8: Top 30 fish species
Top 30 fish species with highest contribution to overall fish biomass
Trophic/Family Taxon Min length (cm) Mean length (cm) Max length (cm) Frequency (% stations) Abundance (ind/m2)1 Biomass (g/m2)1
Planktivore
Fusilier Pterocaesio tile 15.5 21.08 28.5 65.56 0.50 (4.59 %) 65.69 (10.64 %)
Surgeonfish Naso hexacanthus 35.0 49.13 60.0 60.00 0.03 (0.30 %) 56.37 (9.13 %)
Fusilier Caesio teres 12.0 22.88 32.5 48.89 0.16 (1.42 %) 28.42 (4.61 %)
Snapper Macolor macularis 10.0 42.72 60.0 80.00 0.02 (0.17 %) 27.83 (4.51 %)
Fusilier Pterocaesio randalli 16.0 19.23 25.0 24.44 0.22 (2.02 %) 21.78 (3.53 %)
Fusilier Caesio lunaris 20.0 23.88 32.5 30.00 0.06 (0.58 %) 21.54 (3.49 %)
Surgeonfish Acanthurus thompsoni 7.5 16.63 23.0 73.33 0.11 (1.04 %) 12.37 (2.00 %)
Fusilier Pterocaesio pisang 9.5 14.12 17.5 21.11 0.30 (2.77 %) 12.29 (1.99 %)
Surgeonfish Naso vlamingii 20.0 37.56 55.0 73.33 0.01 (0.13 %) 11.27 (1.83 %)
Damselfish Chromis ternatensis 2.0 6.57 10.5 74.44 0.88 (7.98 %) 10.64 (1.72 %)
Damselfish Lepidozygus tapeinosoma 4.0 7.26 10.5 25.56 1.27 (11.58 %) 9.97 (1.62 %)
Surgeonfish Naso annulatus 50.0 62.26 76.5 22.22 0.00 (0.02 %) 8.45 (1.37 %)
Fusilier Pterocaesio tessellata 14.0 19.20 25.0 15.56 0.07 (0.66 %) 7.76 (1.26 %)
Damselfish Pycnochromis margaritifer 2.5 4.96 5.5 87.78 3.08 (28.13 %) 7.36 (1.19 %)
Soldierfish Myripristis berndti 7.0 22.26 29.0 56.67 0.04 (0.34 %) 7.21 (1.17 %)
Damselfish Chromis xanthochira 8.5 12.79 14.0 38.89 0.11 (0.98 %) 7.20 (1.17 %)
Soldierfish Myripristis kuntee 13.0 16.52 21.0 63.33 0.06 (0.53 %) 5.54 (0.90 %)
Damselfish Chromis xanthura 5.0 12.07 15.5 64.44 0.16 (1.43 %) 4.90 (0.79 %)
Top-predator
Snapper Lutjanus bohar 8.0 40.42 80.0 68.89 0.01 (0.08 %) 13.85 (2.24 %)
Jack Caranx sexfasciatus 52.5 56.25 62.5 4.44 0.00 (0.04 %) 12.74 (2.06 %)
Jack Elagatis bipinnulata 30.0 56.34 67.5 13.33 0.01 (0.12 %) 11.88 (1.93 %)
Jack Caranx papuensis 35.0 43.33 55.0 2.22 0.02 (0.15 %) 10.92 (1.77 %)
Jack Caranx melampygus 22.0 44.12 85.0 44.44 0.00 (0.04 %) 7.47 (1.21 %)
Jack Caranx lugubris 18.0 38.60 68.0 28.89 0.00 (0.04 %) 5.37 (0.87 %)
Snapper Lutjanus gibbus 25.0 33.34 41.0 32.22 0.01 (0.10 %) 5.15 (0.83 %)
Lower-carnivore
Wrasse Cheilinus undulatus 28.0 68.69 105.0 16.67 0.00 (0.01 %) 6.93 (1.12 %)
Emperor Monotaxis grandoculis 5.0 34.34 55.0 48.89 0.00 (0.04 %) 5.78 (0.94 %)
Herbivore
Parrotfish Scarus rubroviolaceus 6.0 39.78 65.0 54.44 0.01 (0.05 %) 5.96 (0.97 %)
Parrotfish Chlorurus microrhinos 5.0 44.64 65.0 35.56 0.00 (0.03 %) 5.05 (0.82 %)
Surgeonfish Naso unicornis 38.0 46.67 58.0 15.56 0.00 (0.02 %) 4.98 (0.81 %)
1 Percent contribution in parenthesis

Community assemblages

Table 9: Fish assemblages Adonis model
Figure 15: Principal coordinates analysis
Table 10: Results of ANOVA on the ordination model